1. Field of the Invention
This invention relates to a fuel injection system for an internal combustion engine, such as a diesel engine.
2. Description of the Prior Art
Diesel engines are susceptible to noisy combustion or detonation. This is caused by ignition lag resulting in the supply of an excessive quantity of fuel into combustion chambers prior to complete ignition.
Some fuel injection systems provide pilot fuel injection in advance of the main charge of fuel. The pilot charge of fuel facilitates ignition of the main charge of fuel, thereby reducing ignition lag and preventing noisy combustion and detonation.
Japanese patent publication 56-56962 discloses one such fuel injection system. In application of this injection system to a three-cylinder engine, pilot fuel charge occurs at an unacceptable timing, specifically at a point during the air intake stroke excessively remote from the compression stroke. For best results, the timing of pilot fuel injection should reside essentially within the compression stroke.